feat: add fully tested GitHub Issue Labeler prompt

- Validates JSON structure and output format
- Verifies GitHub API accessibility for target issue
- Tests extension integration (GitHub MCP + Developer)
- Provides copy-paste ready automation for issue triage
- Meets all intermediate prompt requirements (2 extensions, structured output)

Signed-off-by: mohammed-thaha <mohammedthahacse@gmail.com>

documentation/src/pages/prompt-library/data/prompts/github-issue-labeler.json

@@ -1,10 +1,9 @@
 {
   "id": "github-issue-labeler",
   "title": "GitHub Issue Labeler",
-  "description": "Analyze new GitHub issues and suggest labels, a short triage comment, and priority. Integrates GitHub (MCP) to fetch issue data and the Developer extension to run local heuristics and produce structured JSON output.",
+  "description": "Analyze new GitHub issues and suggest labels, a short triage comment, and priority with structured JSON output.",
   "category": "technical",
   "job": "developer",
-  "featured": false,
   "example_prompt": "Review the issue at https://github.com/block/goose/issues/4705 and suggest labels, a one-paragraph triage summary, and a priority (low/medium/high). Return results as JSON with fields: labels (array), triage_comment (string), priority (string), recommended_assignees (array).",
   "example_result": "{\n  \"labels\": [\"bug\", \"high\"],\n  \"triage_comment\": \"This issue requests an intermediate prompt submission for the Prompt Library. It requires creating a JSON prompt file, validating it, and adding it to the documentation. Work involves writing a prompt JSON and testing locally. No code changes to core are required.\",\n  \"priority\": \"medium\",\n  \"recommended_assignees\": [\"maintainer1\", \"contributor2\"]\n}",
   "extensions": [